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| Titel |
Pick-up ion energization in the outer heliosphere due to bulk velocity fluctuations |
| VerfasserIn |
H.-J. Fahr  , M. Siewert |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059548
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| Zusammenfassung |
| At large solar distances beyond 10 AU MHD turbulence amplitudes are decreasing and even selfgenerated turbulences by pick-up ions will not support effectively enough energy diffusion processes driven by nonlinear wave-particle interactions. This should suppress the evolution of suprathermal ion tails beyond the pick-up ion injection border, though at distances beyond 10 AU such tails have been observed by spacecraft like Voyager-1/2, Cassini, and Horizon. We want to show here that an effective process of ion energy diffusion is driven by solar wind bulk velocity fluctuations passing over co-moving ions. Describing such fluctuations as traveling MHD shocks we describe kinetically the ion processing in momentum space and can identify this with an energy diffusion process with a distance-independent diffusion coefficient. As we show this process will lead to the appearance of suprathermal ion power law tails as observed by in-situ spectral ion observations. |
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